Transition "Mystery" Color PETG
What is "Mystery" color?
Coex 3D Transition "Mystery" Color filament is the same high-quality PETG that our customers trust but in "mystery colors". These varying colors are the result of our changeovers from one of our standard colors to another during the production of our filament and cannot be reproduced. While supplies last. Items are not returnable or refundable due to color. "Mystery" color filament is limited to availability as we make changeovers. If you cannot add it to your cart, we are sorry, but we are out of stock.
Note: These are not a rainbow filament. The color change in each spool will vary and be very gradual.
PETG (PolyEthylene Terephthalate plus Glycol) is a co-polyester used in 3D printing for its durability, impact resistance, and temperature resistance. PETG is the second most popular 3D printing filament behind the ubiquitous PLA. It has qualities comparable to ABS but can be printed without an enclosure or fume handling requirements. Unlike ABS, however, PETG cannot be vapor smoothed using acetone.
All of Coex's filament is made in our production facility located in Wisconsin, USA. Coex 3D uses industrial-grade extruders and laser measuring quality control to ensure quality, consistency, and a 1.75±0.03mm diameter specification with every spool. We provide filament that gives excellent-looking and strong prints.
Recommended Print Settings
Coex 3D recommends the following settings when printing with our PETG. Settings will vary depending on your specific print setup.
- Hotend Temperature: 230 °C - 245 °C
- Bed Temperature: 70 °C - 90 °C
- Heated Bed Recommended
- Recommended Build Surfaces/Adhesives:
- PEI Build Surface
- Glass Build Surface
- Magigoo
- Glue Stick
- Painter's Tape
- Cooling Fan: Recommended. PETG works best with slightly less cooling than PLA. 50-75% fan speed is recommended.
- IMPORTANT NOTE! PETG can fuse to glass and PEI print surfaces, causing damage to the print bed when the part is removed. For that reason, Coex 3D recommends always using an additional adhesion agent (such as glue stick or Magigoo) which will help the finished part to release from the print bed.
Other Printing Tips
- PETG is slightly more hygroscopic than PLA, so drying your filament can be necessary if it is exposed to humidity. Coex 3D recommends drying our PETG at 65 °C for at least 3 hours. You can tell when your filament needs drying if you experience under-extrusion/inconsistent extrusion, and/or excess stringing. Hearing a "popping" sound during a print is another sign of filament that needs to be dried.
- PETG can often result in more stringing than would be expected with PLA or similar filaments. There are a few steps you can take to reduce stringing:
- Reduce print temperature. Keep in mind that reducing print temperature will slightly decrease layer adhesion and part strength, but can help reduce stringing.
- Increase retraction. Increasing retraction length can help reduce stringing, especially on Bowden-style extrusion configurations.
- Enable "Wipe while Retracting" in your slicer. Most slicers allow for this option, which will start a travel move just before/during the filament retraction. This helps "wipe off" the nozzle as a travel move starts, reducing stringing.
- Enable "Combing Mode" (Cura) or "Avoid Crossing Perimeters" (PrusaSlicer/SuperSlicer/etc.). Rather than travel moves always going in a straight line, this will cause them to choose a path that avoids crossing over perimeters, effectively keeping the nozzle "inside" the print area wherever possible. This eliminates stringing right at the source but still cannot eliminate it all (such as between multiple parts).
- Unfortunately in many cases stringing is impossible to fully eliminate, so some post-processing of prints is often necessary.
Technical Printing Guide - COEX PETG
1. Material Notes
- Keep filament dry - store properly and dry before use
- If needed, dry at 65°C for 3 hours or more
- Enclosure is helpful but not mandatory
- Use Z-offset slightly higher than PLA (+0.05mm)
- Enable "Avoid crossing perimeters" to reduce stringing
- Consider using the "Wipe while retract" option
- Enable "Slow down for small perimeters."
- Print outer walls slower for better quality
- Use a minimum layer time of 30 seconds for small parts
- Enable cooling gradually after the first layer
- Consider using "Extra Prime Amount" after retraction
2. Basic Parameters
| Nozzle | Layer Height | Line Width | Volumetric Speed | Temperature |
| 0.4mm | 0.2mm | 0.42mm | 14.0 mm³/s | 235°C |
| 0.6mm | 0.3mm | 0.62mm | 31.5 mm³/s | 235°C |
| 0.8mm | 0.4mm | 0.82mm | 56.0 mm³/s | 240°C |
| 1.0mm | 0.5mm | 1.02mm | 87.5 mm³/s | 245°C |
3. Speed Settings
0.4mm Nozzle (Volumetric Speed: 14.0 mm³/s)
| Line Type | Percentage | Speed |
| External Perimeter | 50% | 83.33 mm/s |
| Internal Perimeters | 75% | 125.00 mm/s |
| Infill | 100% | 166.67 mm/s |
| Top/Bottom | 60% | 100.00 mm/s |
| First Layer | 30% | 50.00 mm/s |
0.6mm Nozzle (Volumetric Speed: 31.5 mm³/s)
| Line Type | Percentage | Speed |
| External Perimeter | 50% | 84.68 mm/s |
| Internal Perimeters | 75% | 127.02 mm/s |
| Infill | 100% | 169.35 mm/s |
| Top/Bottom | 60% | 101.61 mm/s |
| First Layer | 30% | 50.81 mm/s |
0.8mm Nozzle (Volumetric Speed: 56.0 mm³/s)
| Line Type | Percentage | Speed |
| External Perimeter | 50% | 85.37 mm/s |
| Internal Perimeters | 75% | 128.05 mm/s |
| Infill | 100% | 170.73 mm/s |
| Top/Bottom | 60% | 102.44 mm/s |
| First Layer | 30% | 51.22 mm/s |
1.0mm Nozzle (Volumetric Speed: 87.5 mm³/s)
| Line Type | Percentage | Speed |
| External Perimeter | 50% | 85.78 mm/s |
| Internal Perimeters | 75% | 128.68 mm/s |
| Infill | 100% | 171.57 mm/s |
| Top/Bottom | 60% | 102.94 mm/s |
| First Layer | 30% | 51.47 mm/s |
4. Retraction Settings
IMPORTANT: Set travel speed to the maximum your machine allows (200-500mm/s). Faster movements reduce filament oozing time, minimizing stringing.
| Nozzle | Distance | Speed | Z-Hop |
| 0.4mm | 1.0-1.5mm | 40mm/s | 0.2mm |
| 0.6mm | 1.0-1.5mm | 40mm/s | 0.2mm |
| 0.8mm | 1.0-1.5mm | 40mm/s | 0.2mm |
| 1.0mm | 1.0-1.5mm | 40mm/s | 0.2mm |
5. Temperature Settings
Bed Temperature: 70-90°C
- Wash the bed often for good adhesion - Use dish soap and rinse thoroughly to remove oils
- Use bed adhesion products if necessary (gluestick, WELD3D)
- Use brim for tall or large prints
- Keep the ambient temperature stable
Extruder Temperature: 230-245°C
6. Cooling Settings
Cooling Configuration:
Fan Speed Settings:
- First Layer: 0% (fan off)
- General Printing: 40% fan speed
- Bridges and Overhangs: 70% fan speed
- Layers < 30 seconds: 70% fan speed
Advanced Settings:
- Keep Fan Always On: YES
- Force Fan Speed for Overhangs: YES
- Minimum Layer Time: 30 seconds
- Force Fan Speed for Small Perimeters: YES
Additional Cooling Notes:
- Enable gradual fan speed increase after the first layer
- Increase fan speed for small, detailed parts
- Consider reducing fan speed for better layer adhesion if needed
- Monitor overhangs and bridge quality to adjust fan speed
7. Troubleshooting Guide
| Problem | Solution |
| Irregular extrusion |
1. Dry the filament 2. Check the extruder 3. Reduce speed |
| Poor adhesion |
1. Dry the filament 2. Use adhesive 3. Adjust the first layer |
| Stringing |
1. Dry the filament 2. Adjust retraction 3. Increase travel speed 4. Check temperature |
PLEASE NOTE: These printing parameters are initial recommendations based on our experience. They may need adjustment depending on your specific 3D printer, environmental conditions, and the geometry of the part you are printing. Use these settings as a starting point and fine-tune them according to your specific needs.
Customer Reviews
The mystery PETG was a nice roll of black. I threw it up on my BambuLab A1 printed a planetary fidget spinner and samurai sword and both printed perfectly no stringing very smooth. Very impressed posted results on Tick Tok
Excellent - the Mystery filaments will all print just as well as their counterparts in a 'real' color, it's the same high quality raw materials but it's simply produced when we transition from one color to the next during manufacturing.
Awesome!!
Great
I do a lot of cosplay and prototypes where the color doesn't matter, so I've switched to this filament because it's a bit more affordable than the solid colors. (I print A LOT of big stuff)
I originally thought this mystery stuff was a somewhat gimmicky, but it is actually really neat because you will get to see all the colors that you haven't been able to experience or haven't been able to buy yet. Think of it as a sample roll of two colors in each box. Some of them are actually quite eye-popping.
A lot of the early rolls were a mixture of army green or grey, but lately I get a good blend of neons and bright colors.... And the color transition is usually a very visible and defined purge section in the middle, so if you plan your prints right, you can ACTUALLY have two prints with their own solid color/material and no transition.
The last roll I used was the new matte black with a gloss black transition and was able to see what the new matte black material looks like on a print without ever buying a roll or getting a sample, so thumbs up to that.
As always filament prints great on my printers out of the box, but this does suck up the water especially during the summers in the Midwest, so make sure to dry before using.
I bought this because I do a lot of stuff where color doesn't matter. This roll started out jet black and is getting lighter. Truthfully, I see it in the filament but not the final prints. I'm glad Coex offers this rather than reprocessing or wasting or whatever is done with it.